Over my lifetime, more still over the past century, the cultural and political institutions of the U.S. have changed substantially, for reasons that have very little to do with immigration. Over the past million years, the climate of the earth has changed radically, time after time, for reasons that have nothing to do with anthropogenic CO2. A rise in sea level of a foot or two would create problems in some parts of the world, but not problems comparable to the effect of half a mile of ice over the present locations of Chicago and London.The conservative mistake comes with its own pseudoscientific slogan, "the precautionary principle." It is the rule that no decision should be made unless one can be confident that it will not have substantial bad effects—the lack of any good reason to believe it will have such effects is not enough.I have long argued that the principle is internally incoherent. The decision to (for example) permit nuclear power could have substantial bad effects. The decision not to permit nuclear power could also have substantial bad effects. If one takes the precautionary principle seriously, one is obligated to neither permit nor forbid nuclear power…I am not arguing that there is never a good reason to fear change—sometimes a change can be reasonably predicted to have bad consequences. I am arguing that much opposition to change, across a wide range of different topics and disputes, is based on the mistaken assumption that if only that particular change is prevented, the next year, the next decade, perhaps even the next century, will be more or less the same as the present.That is very unlikely.
This profound insight is from Economic Professor David Friedman on his blog discussing why the political hand waving against change is a mistake.